The DB2® High Availability and Disaster Recover (HADR) feature is a database replication method that provides a high availability solution for both partial and complete site failures. HADR protects against data loss by replicating data changes from a source database, called the Primary, to a target database, called the Standby.

The HADR reads on standby (HADR ROS) feature, allows applications to access the current Standby databases for reads. With the HADR ROS feature, read/write applications can access the HADR Primary database, and read-only applications can access either the HADR Primary or the HADR Standby database. This enables you to offload some of the read-only workloads running on the Primary to the Standby.

This paper shows how you can use the HADR ROS feature in conjunction with Virtual IP addresses to ensure continued, automatic connectivity for read-only clients.